From 779b072fbff3990259f8452c516689d6fcbc47ed Mon Sep 17 00:00:00 2001
From: Bagatur <baskaryan@gmail.com>
Date: Thu, 3 Oct 2024 14:48:31 -0700
Subject: [PATCH 1/2] core[minor]: exclude model cache from serialization

---
 langchain-core/src/language_models/base.ts | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/langchain-core/src/language_models/base.ts b/langchain-core/src/language_models/base.ts
index 80e1fa434969..827ea2263291 100644
--- a/langchain-core/src/language_models/base.ts
+++ b/langchain-core/src/language_models/base.ts
@@ -363,13 +363,15 @@ export abstract class BaseLanguageModel<
     callbackManager,
     ...params
   }: BaseLanguageModelParams) {
+    const cache = params.cache;
+    delete params.cache;
     super({
       callbacks: callbacks ?? callbackManager,
       ...params,
     });
-    if (typeof params.cache === "object") {
-      this.cache = params.cache;
-    } else if (params.cache) {
+    if (typeof cache === "object") {
+      this.cache = cache;
+    } else if (cache) {
       this.cache = InMemoryCache.global();
     } else {
       this.cache = undefined;

From 430e0a7086b95bf8ad75f0198c164be7ac5e0ba2 Mon Sep 17 00:00:00 2001
From: jacoblee93 <jacoblee93@gmail.com>
Date: Thu, 3 Oct 2024 15:51:40 -0700
Subject: [PATCH 2/2] Add test, fix lint

---
 langchain-core/src/language_models/base.ts           |  5 ++---
 .../src/language_models/tests/chat_models.test.ts    | 12 ++++++++++++
 langchain-core/src/utils/testing/index.ts            |  7 +++++--
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/langchain-core/src/language_models/base.ts b/langchain-core/src/language_models/base.ts
index 827ea2263291..4f1233426724 100644
--- a/langchain-core/src/language_models/base.ts
+++ b/langchain-core/src/language_models/base.ts
@@ -363,11 +363,10 @@ export abstract class BaseLanguageModel<
     callbackManager,
     ...params
   }: BaseLanguageModelParams) {
-    const cache = params.cache;
-    delete params.cache;
+    const { cache, ...rest } = params;
     super({
       callbacks: callbacks ?? callbackManager,
-      ...params,
+      ...rest,
     });
     if (typeof cache === "object") {
       this.cache = cache;
diff --git a/langchain-core/src/language_models/tests/chat_models.test.ts b/langchain-core/src/language_models/tests/chat_models.test.ts
index 70ff187243e8..f335d5edc40f 100644
--- a/langchain-core/src/language_models/tests/chat_models.test.ts
+++ b/langchain-core/src/language_models/tests/chat_models.test.ts
@@ -323,3 +323,15 @@ test("Test ChatModel can stream back a custom event", async () => {
   }
   expect(customEvent).toBeDefined();
 });
+
+test(`Test ChatModel should not serialize a passed "cache" parameter`, async () => {
+  const model = new FakeListChatModel({
+    responses: ["hi"],
+    emitCustomEvent: true,
+    cache: true,
+  });
+  console.log(JSON.stringify(model));
+  expect(JSON.stringify(model)).toEqual(
+    `{"lc":1,"type":"constructor","id":["langchain","chat_models","fake-list","FakeListChatModel"],"kwargs":{"responses":["hi"],"emit_custom_event":true}}`
+  );
+});
diff --git a/langchain-core/src/utils/testing/index.ts b/langchain-core/src/utils/testing/index.ts
index f14629794293..59f8c8437662 100644
--- a/langchain-core/src/utils/testing/index.ts
+++ b/langchain-core/src/utils/testing/index.ts
@@ -354,6 +354,8 @@ export class FakeListChatModel extends BaseChatModel<FakeListChatModelCallOption
     return "FakeListChatModel";
   }
 
+  lc_serializable = true;
+
   responses: string[];
 
   i = 0;
@@ -362,8 +364,9 @@ export class FakeListChatModel extends BaseChatModel<FakeListChatModelCallOption
 
   emitCustomEvent = false;
 
-  constructor({ responses, sleep, emitCustomEvent }: FakeChatInput) {
-    super({});
+  constructor(params: FakeChatInput) {
+    super(params);
+    const { responses, sleep, emitCustomEvent } = params;
     this.responses = responses;
     this.sleep = sleep;
     this.emitCustomEvent = emitCustomEvent ?? this.emitCustomEvent;